Metallic ink composition for wick type writing instruments

ABSTRACT

An ink composition or system for writing instruments constructed with a polyester fiber reservoir and a porous oriented fiber nib. This ink system will write on both black and white surfaces. On black surfaces, it will reveal itself as being opaque and metallic almost iridescent in appearance. On white surfaces, a tint of color is observed with distinct flecks of silver. The ink system is composted of water as a carrier, a permanent water-based binder, a colored pigmented permanent water-based dispersion of sub-micron particle size, a unique aluminum dispersion of specific particle size in a special carrier, a humectant, a surfactant that lowers surface tension, an anti-settling additive, a preservative and a base acting as a pH adjuster.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to metallic ink based writinginstruments and, more particularly, to metallic ink compositions forwick type writing instruments.

[0002] Currently, metallic ink writing instruments are enjoying greatpopularity. These are almost entirely in the form of a conventionalstyle marker currently called a valve action marker (see FIG. 1). Fromthe diagram, one can see that this is a complex device involvingelaborate assembly. The valve action marker also involves shaking backand forth and then depressing, or pumping, the nib several times beforeink will come down. As one can see, this is a rather cumbersome process.

[0003] Historically, metallic pigments have a large particle sizegreater than 20 microns; therefore, passage through a wick-style markerhas not been possible. Instead, a valve-action marker is constructedwith two steel balls in its ink chamber and a spring mechanism at thefront in contact with the nib or tip. Since the specific gravity of thealuminum pigment is greater than water, it tends to settle rapidly. Thisis overcome by shaking back and forth, thereby re-mixing the aluminumparticles in the ink. The pumping action on the paper forces the largeparticle aluminum pigments through the tip by applying pressure throughthe tip, thereby, producing ink and making writing possible.

[0004] Related conventional art includes U.S. Pat. No. 5,013,543 toMercado; U.S. Pat. No. 5,219,560 to Kazuhiro; U.S. Pat. No. 5,106,881 toHiroshi; U.S. Pat. No. 4,761,277 to Valdes; U.S. Pat. No. 4,872,905 toBourne and U.S. Pat. No. 4,604,139 to Shoi, the contents of which areincorporated by reference herein. Regardless, the prior art has notdelivered to date a wick-style marker which can deliver metallicpigments, i.e. inks, in writing instruments. As a result, metallic inkwriting instruments have been more expensive, more complex to build andmaintain, less reliable and have not fully realized their potential.

SUMMARY OF THE INVENTION

[0005] The general object of the present invention is to providemetallic ink compositions that work reliably in wick type writinginstruments.

[0006] The foregoing and other objects of the invention are realized bythe present invention which shows how one can overcome theaforementioned drawbacks of the prior art using a comparativelyinexpensive wick-style marker that works by capillary action eliminatinga costly assembly process.

[0007] The objects of the invention are achieved by mainly utilizing:

[0008] 1. A small particle size aluminum dispersion less than 12microns;

[0009] 2. an anti-settling agent to keep aluminum flakes in suspension;

[0010] 3. a densely packed highly porous polyester fiber filler;

[0011] 4. a highly porous oriented polyester fiber nib with manychannels;

[0012] 5. a non-volatile humectant; and

[0013] 6. a sub-micron colored pigmented dispersion.

[0014] This invention will work for a conventional simple wick-stylemarker that carries a cylindrical shaped reservoir (filler) that absorbsthe ink and transports it to a porous oriented fiber nib that feeds onthe filler by capillary action (see FIG. 2).

[0015] The invention results in a minimum of metallic particles settlingout. The marker can be stored either vertically or horizontally;overcoming a traditional problem associated with pigmented ink systems.This wick-ink system, when filled into the writing device (FIG. 2), willalso lay-down a thick opaque line capable of being seen on both blackand white surfaces.

[0016] Traditional inks that work with pens (FIG. 2) cannot write onblack paper since they are translucent, therefore, this market has beenoccupied by the valve-action marker of FIG. 1 which permits the flow oflarge particle size pigments. This invention solves this problem in awick-style writing instrument (FIG. 2) that is user friendly and muchsimpler, not to mention a cheaper alternative.

[0017] The present invention is based on the startling discovery thatbased on the disclosed, specific ink formulation, a writing instrumentcan be made that carries a cylindrical shaped reservoir which feeds intoa fiber nib by capillary action and remains for extended periods withoutsettling out or blocking the nib or tip. This invention also eliminatesthe use of an expensive valve type marker.

[0018] Thus, an object of the invention is that a single wick-type pencan be used to write on both black and white surfaces and achieve ametallic almost iridescent appearance.

[0019] Another object of the invention is a pen that may possibly beused for decorative poster work on both black and white surfaces.

[0020] A further object of the invention is the ability to write onhuman skin to achieve decorative effects similar to temporary tattoos,with an intense opaque metallic look, and washable with soap and water.

[0021] Still further, an object of this invention is to attain, bychanging the permanent binder to a temporary one, a damp erase or dryerase writing instrument that can be made to write on black and whitemelamine, porcelain and all non porous boards.

[0022] The invention composition includes water as a carrier, an acrylicresin in solution as a binder although a polyvinylpyrrolidone polymercan be substituted to make temporary inks, a pigmented dispersion as acoloring agent, a unique aluminum dispersion of particle size 1 to 12microns, a surfactant to reduce surface tension, an anti-settling agentto suspend aluminum particles along with a preservative, and a pHadjuster in the form of an amine.

[0023] The components of the writing instrument utilized in thisinvention are of some importance. The polyester filler, or reservoirchosen, must be densely packed and porous to allow flow of aluminumparticles and at the same time keep settling to a minimum. Polyesterfiber is chosen because it is non-reactive and very porous. The tip, ornib, of the writing instrument must be a porous, oriented polyester nibthat has many channels to allow aluminum pigments to pass freely. Manyother types of fibers will filter the aluminum and only allow thecolored pigment to pass through, thus creating a non-metallicappearance.

[0024] One additional detail should be noted about this invention. Dyesare not used in this composition. This is because dyes wash away easily,they do not provide bonding to the aluminum pigments and are more of anoutline as described in U.S. Pat. No. 4,604,139.

[0025] This invention utilizes a permanent and semi-permanent opaquemetallic ink, which may display iridescent qualities depending on thesurface written on—black or white.

[0026] Other features and advantages of the present invention willbecome apparent from the following description of the invention whichrefers to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 diagrammatically illustrates a conventional valve actionink dispensing writing implement.

[0028]FIG. 2 illustrates a conventional, wick-style writing implement.

DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention illustrates the considerable ease andconvenience of an ink system in a simple wick type writing instrument(FIG. 2), compared to the complexity of conventional valve-actionmarkers (FIG. 1) that are currently used to deliver metallic inks.

[0030] This invention is accomplished by providing an aqueous one-phaseink composition having a viscosity of 5 cps to 10 cps at 25° Celsiuswith a pH of 7.5 to 8.5 suitable for use in a wick-style writinginstrument with a porous oriented fiber nib.

[0031] This ink system contains an aluminum pigmented dispersion of nogreater particle size than about 12 microns, a sub-micron pigmentedcolored aqueous dispersion to impart a tint and contribute topermanency, an anti-settling agent to keep aluminum particles fromsettling out, and a binder to bind the aluminum pigments together and toimpart adhesion, water resistance, gloss, and permanency to differentsurfaces.

[0032] In addition to the foregoing important ingredients, this inksystem may contain other additives including a preservative, asurfactant to reduce surface-tension, a pH adjuster in the form of anamine, and a rheology modifier such as a starch or clay.

[0033] As noted before, one of the important aspects of the presentinvention is the particle size of the aluminum pigments. If the particlesize is too large, greater than 12 microns, they will not flow throughthe pathways of the filler and nib. This is one of the main reasons whymetallic inks have been confined to be used only in valve markers (FIG.1), which is essentially a free-flowing system, and the pumping actionimparts pressure on the aluminum particles forcing them through the nib.

[0034] The present invention solves the problem by using a carefullymonitored particle size aluminum dispersion, along with a customizedfiller of high density with many pathways, and a highly porous orientedfiber nib with many channels.

[0035] The aluminum flakes are dispersed initially in water and binderof starch with the pH adjusted anywhere between 7.0 and 8.0. Thisprevents the build up of hydrogen gas, which is a notorious anddangerous problem associated with aluminum pigments. The finished inksystem is adjusted to a pH of 7.5 to 8.5; this is to ensure this problemdoes not occur.

[0036] The dispersion used in the present invention is of the type StapaHydrolac AW from Eckart and Roto Vario from Eckart. The amount needed toimpart a metallic look varies from about 10% to 25% by weight dependingupon the desired intensity of the color.

[0037] It is very interesting to note that on black surfaces, thepigmented color and the aluminum pigments bond together to impart auniform metallic line. On white paper, the color is separated from themetallic flakes showing a line that is tinted in color and flecked withaluminum to impart a silver appearance.

[0038] The aluminum dispersions of the present invention are very stableat temperatures of 100° F. to 125° F. and do not dry up easily. Thiscontributes to the long shelf life of the marker. For this ink system tobe stable, the starch which bonds the aluminum flakes in the dispersionhave even more cohesion with the marker binder of the system therebycontributing to it staying in solution and keeping the aluminum flakessuspended.

[0039] The binder in the present invention is an acrylic resin solutionof about 40% to 50% solids. This binder forms a clear film at roomtemperature on drying. It is resistant to water and adheres well to mostsurfaces. The pH is between 7.5 and 8.5. The viscosity is 100 to 150 cpsand the glass transition temperature t.g. ° C30. The binder must be ableto form a film at room temperature. This is the only way the aluminumflakes will bond to writing surfaces on drying. Typical resins of thistype include GA-1590 from B. F. Goodrich and Joncryl 537 from S. C.Johnson.

[0040] Many other polymers will come to mind of those skilled in theart. The binder is used at about 10% to 25% by weight depending on thedesired resistance properties.

[0041] The pigmented colored dispersion is of great importance sincethis dispersion imparts the desired color to the overall metallic inksystem and makes it pleasing to the eye. The present invention utilizesa dispersion of about 35% to 45% solids, pH 8.0 to 9.0, and viscosity of100 to 150 cps at 25° C. The pigments are grounded in an acrylic binderor surfactant to a particle size less than 0.5 micron enhancing theirbonding ability to the aluminum pigments. Common dispersions used in theinvention include Heucosperse colors from Heucotech and Acroverse colorsfrom Penn Color. A percentage of 10% to 20% by weight is used dependingon the desired color intensity.

[0042] The anti-settling agent additive is of particular importancebecause of the aluminum flakes readiness to settle out. The ioniclycharged sites on the additive bond themselves to the aluminum flakessuspending them in solutions for extended periods and keeping themtightly adhered to the surfaces of the colored pigments. This ensuresthat the ink traveling down the polyester filler into the nib and ontothe writing surfaces is metallized. Without the anti-settling agent, thealuminum flakes would separate very quickly from the colored pigments.The resulting system will be one that writes very non-uniform by, withcolored lines appearing with no metallic appearance. The anti-settlingagent utilized in this invention is ionic in nature and derived from apolycarboxylic acid. Examples are phtalic acid, adipic acid andtri-metallic acid. A percentage of 0.25% to 1.5% by weight is utilized,an example of this agent is BYK105 from Byk Chemie.

[0043] A humectant is utilized in this invention to keep the finishedwriting instrument from drying out on extended storage in warm and humidconditions. Polyglycols are particularly adept in these applications,although glycerin may be utilized. This invention uses Polyglycols ofmolecular weight of 400 to 725 at about 5% to 10% by weight. Examplesare Carbowax 400 and Carbowax 700 distributed by Pride Chemicals.

[0044] With many water based ink systems the surface tension is veryhigh. A surfactant helps reduce this property so that proper flowthrough the filler and wetting on different surfaces are achieved. Thisink composition has a surface tension of about 37 to 40 dynes/cm andutilizes a fluro chemical surfactant similar to one provided by 3MFC-170C and zonyl FSN supplied by DuPont Chemicals. A percentage of 0.5%to 0.75% by weight is used in this invention.

[0045] To discourage improper use of the marker a water-soluble organicsolvent such as denatured ethanol is utilized in this invention. Thisalso contributes to its drying speed on different surfaces. An examplewould be SOF-642 distributed by Pride Chemicals. A quantity of 3% to 10%is utilized.

[0046] As mentioned before, the ink system needs to be maintained at apH of 7.0 to 8.5 so as to avoid the build up of hydrogen gas. Therefore,an amine pre-mixed with water to avoid shocking the aluminum flakes isutilized to adjust and stabilize the pH. This invention usesTriethanolamine (99%) at about 0.25% to 1.0% by weight, distributed fromPride Chemicals. Other common amines such as AMP-95 distributed by AngusChemicals can also be used.

[0047] Finally, a preservative is utilized to keep fungi and bacteriafrom build up in the writing instrument on extended storage. A number ofpreservatives will come to mind of one skilled in the art. The preferredproduct in this invention is Germaben II from ISP Polymers used at 1.0%to 3.0% by weight.

[0048] The following examples will demonstrate this ink system thatutilizes a simple wick-style marker (FIG. 2).

[0049] All figures are percentage by weight. Red Permanent Metallic InkDistilled Water 57.00 B. F. Goodrich GA1594 10.00 Pride ChemicalCarbowax 400 5.00 Eckart Stapa Hydolac AW 15.00 Penn Color Acroverse Red5123 10.50 ISP Polymers Germaben II 1.25 Pride ChemicalTriethylanolamine 99% 0.25 Byk Chemie Byk 105 1.00 100.00

[0050] Blue Permanent Metallic Ink Distilled Water 42.25 B. F. GoodrichGA1594 10.00 Pride Chemical Carbowax 400 5.00 Eckart Roto Vario RV500025.00 Heuback Heucosperse BS5525 15.00 ISP Polymers Germaben II 1.25Pride Chemical Triethylanolamine 99% 0.50 Byk Chemie Byk 105 1.00 100.00

[0051] Green Permanent Metallic Ink Distilled Water 50.25 S. C. JohnsonJoncryl 537 11.00 Pride Chemical Carbowax 400 4.00 Eckart Roto VarioRV5008 20.00 Penn Color Acroverse Green 32G120 12.00 ISP PolymersGermaben II 1.25 Angus Chemical AMP-95 0.25 Byk Chemie Byk 105 1.25100.00

[0052] Gold Permanent Metallic Ink Distilled Water 44.50 S. C. JohnsonJoncryl 537 10.00 Pride Chemical Carbowax 400 7.00 Heubach HeucosperseIII YS5345 15.00 Eckhart Roto Vario RV5008 20.00 ISP Polymers GermabenII 2.00 Angus Chemical AMP-95 0.25 Byk Chemie Byk 105 1.25 100.00

[0053] Semi-Permanent Wet Erase Metallic Ink For Black and WhiteMelamine, Porcelain and All Non Porous Boards Blue Ink Wet EraseMetallic Distilled Water 63.75 Pride Chemical Carbowax 400 7.00 ISPTechnologies PVP/VA630 2.00 Heubach Heucosperse 33S5528 10.00 EckhartRoto Vario RV5008 15.00 ISP Technologies Germaben II 1.00 Angus ChemicalAMP-95 0.25 Byk Chemie Byk 105 1.00 100.00

[0054] Red Ink Wet Erase Metallic Distilled Water 67.75 Pride ChemicalCarbowax 400 4.00 Penn Color Heucosperse Red 5123 15.00 ISP TechnologiesGermaben II 1.00 Eckart Roto Vario RV5308 10.00 Pride ChemicalTriethanolamine 99% 0.50 Byk Chemie Byk 105 0.75 ISP PVP/VA 670 1.00100.00

[0055] Summarizing, the present invention comprises a metallizing systemfor writing instruments having a densely packed polyester fiberreservoir and a porous polyester oriented fiber nib with channelsallowing passage of specific particle size aluminum pigment (less than12 microns). This nib is in contact with the reservoir shown in thewriting instrument illustrated in FIG. 2 and the system functions bycapillary action.

[0056] Although the present invention has been described in relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art. It ispreferred, therefore, that the present invention be limited not by thespecific disclosure herein, but only by the appended claims.

What is claimed is:
 1. A writing instrument, comprising: a denselypacked polyester fiber reservoir and a porous polyester oriented fibernib with channels allowing passage of an ink therethrough; an ink systemin the reservoir, the ink system including a color pigmented dispersionand an aluminum pigment of a particle size that is not greater thanabout 12 microns; and the fiber nib being in contact with the reservoirand being able to absorb the aluminum pigment by capillary action. 2.The writing instrument of claim 1 , including; an anti-settling agent tokeep the aluminum particles in suspension; a nonvolatile humectant; andsaid color pigmented dispersion having a sub-micron particle size. 3.The writing instrument of claim 2 , wherein said ink system includes:distilled water as a carrier, at about 40% to 70% by weight; a watersoluble organic solvent having an evaporation rate greater than 1.0 at25° C. using butyl acetate at about 1.0 as a basic; a liquid acrylicresin solution at about a 40% to 50% solids and present in the inksystem from about 10% to 20% by weight; said humectant being selectedfrom a group of polyglycol molecular weight 400 to 1025 and present inthe ink system from about 5% to 15% by weight; an aluminum pigmenteddispersion of about 10% to 15% solids at less than about 12 micronsparticle size and present at 10% to 25% by weight with a pH of about 7.0to 8.5; a fluro chemical surfactant with a pH of about 9.0 and surfacetension of about 25 dynes/cm and present at 0.25% to 1.0% by weight; ananti-settling agent chosen from a lower molecular weight unsaturatedpolycarboxylic acid that has an ionic charge present in an amount 0.25%to 1.25% by weight; and an ammoniacal base for adjusting the pH of theink system to about pH 7.5 to 8.5 present in an amount 0.25% to 1.5% byweight; and a colored water-based pigmented dispersion of about 35% to45% solids having a particle size less than about 0.5 microns andpresent in amount 10% to 20% by weight.
 4. The writing instrument ofclaim 2 , wherein said ink system has one phase with a viscosity of 5cps to 10 cps, a pH of about 8.0 to 8.5, and a surface tension of about37 dynes/cm. which lays down a smooth unbroken opaque metallic line. 5.The writing instrument of claim 2 , wherein this said ink systemincludes a binder that is an acrylic resin solution present at about 10%to 25% by weight selected from a group or class of acrylic resinsolutions that have a t.g. ° C.-16 to 30, MFFT° C.<25° C., a viscosityof about 50 cps to 150 cps, and a solid content of 40% to 50%.
 6. Thewriting instrument of in claim 5 , wherein said binder forms a clearfilm at room temperature and remains stable at temperatures 100° F. to125 ° F. for extended periods to allow for a longer shelf life of theink system.
 7. The writing instrument of claim 2 , including a bindercomprising a polyvinylpyrrolidone polymer at about 1% to 2% by weight,so as to complete a semi-permanent wet erase and/or dry erase metallicink system capable of writing on black and white melamine, porcelain andall non porous boards.
 8. The writing instrument of claim 2 , whereinthis ink system comprises an aluminum-pigmented water-based dispersionwhose particle size is no greater than 12 microns made from brightleafing aluminum flakes.
 9. The writing instrument of claim 8 , whereinsaid aluminum is dispersed in a medium of starch and water to preventsettling and a pH of 8.0 and 8.5 to prevent hydrogen gas build up and isstable at 100° F. to 125° F. so as to prevent drying out of the writinginstrument.
 10. The writing instrument of claim 3 , wherein this saidink system is stable in a slightly alkaline medium and non-reactive withhydrogen gas, and said surfactant is capable of reducing surface tensionand promote flow.
 11. The writing instrument of claim 2 , wherein saidink system includes, as a an anti-settling additive based on a lowermolecular weight, unsaturated polycarboxylic acid with ionic activitythat will bond with aluminum pigments and keep them in suspension forextended periods in a low viscosity ink system.
 12. The writinginstrument of claim 2 , wherein this said anti-settling additiveincreases color strength and prevents hard settling of aluminumpigments.
 13. The writing instrument of claim 2 , wherein this said inksystem utilizes a humectant chosen from a group of polyglycol ofmolecular weight 400 to
 1025. 14. The writing instrument of claim 2 ,wherein this said ink system, includes a preservative to prevent buildup of fungi and bacteria in water-based inks containing diazolidinylurea, methyl paraben, and propyl paraben.
 15. The writing instrument ofclaim 2 , wherein this said ink system includes a pH adjuster in theform of a base capable of stabilizing said system to a pH of 8.0 to 8.5.16. The writing instrument of claim 2 , including a polyester fiberreservoir that is tightly bonded in a wrapped polypropylene skin incontact with a multi-channel highly porous oriented fiber nib containingsaid ink system, said ink system having a viscosity of 5 cps to 10 cpsat 25° C., a surface tension of less than 40 dynes/cm at 25° C., a pHabout 7.0 to 8.5 capable of making permanent or semi-permanent metalliclines on black and white surfaces.
 17. The writing instrument of claim 2, wherein said instrument is capable of making semi-permanent opaquemetallic lines on human skin and nails, similar to temporary tattoos,that are washable with soap and water.
 18. A writing instrument,comprising: a non valve-action body defining an ink reservoir with anopening that is closed off by a fiber nib; and an ink system in thereservoir, the ink system containing an aluminum pigmented dispersion ofnot greater particle size than about 12 microns, a sub-micron pigmentedcolored aqueous dispersion to impart a tint, an anti-settling agent tokeep aluminum particles from settling out, and a binder to bind thealuminum pigments together.
 19. The writing instrument of claim 18 ,further including a preservative, a surfactant to reducesurface-tension, and a pH adjuster.
 20. A method for forming temporarytattoos on human skin, comprising the step of: providing a writinginstrument which includes a densely packed polyester fiber reservoir andporous polyester oriented fiber nib with channels allowing passage of anink therethrough, an ink system in the reservoir, the ink systemincluding an aluminum pigment of a particle size that is not greaterthan about 12 microns, and the fiber nib being in contact with thereservoir and being able to absorb the aluminum pigment by capillaryaction; and movingly pressing the writing instrument against human skinto create temporary tattoos that are in the form of semi-permanentopaque metallic lines.